Shock Absorber Error Codes

Lamborghini Shock Absorber Error Codes

Figure 1. Shock absorber stiffness control

There are six heavy duty shock absorbers under a two ton Lamborghini Diablo. One for each front wheel and two for each rear wheel. This weight puts considerable strain on the six KONI shock absorbers of the car. The softness of these absorbers can be adjusted by the driver by means of "up/down" buttons in a ride control unit located in front of the gear shift leaver of the car. There are 4 possible settings. One being soft, four very stiff, making the car behave almost as if there are no shocks present at all. There is also an "auto" setting which allows the cars computer to match the settings with road conditions and speed. If any of the shocks fail to respond to the onboard computer in the car a red error light will blink in the ride control unit. What can be the problem?

Well for one thing in the post 1994 models, the front of the car can be raised about 4 inches when traveling at low speed by means of a manual switch operated by the driver. This is extremely useful in parking lots and over rough road surfaces. Consequently the front two shock absorbers on these cars is more elaborate in that they are hydraulically controlled (See figure 6). With extended usage they can leak a little oil. This will not only generate an error but lock the unit into a setting 3 stiffness for all road conditions. Other shock absorber failures can also occur. How can we determine which absorber is at fault? Do we have a faulty electrical connection to a shock, or is there something wrong with the shock itself? Fortunately Lamborghini has installed in the car a computer driven series of tests to locate which wheel affected and help diagnose the problem.


Figure 2 Front shock removed showing electrical connection		Figure 3. Rear shocks of Lamborghini Diablo VT		Figure 4. Rear Shocks with wheel removed.

First Test Level.

Figure 5 Shock absorber diagnostic switch

In order to run a shock absorber diagnostic test, the car must be stopped and parked. Turn the ignition is turned off. Now feel under the passenger side front panel for a small box with one switch facing downwards. Pull this switch down and forward. This switch is shown in figure 5. Then turn the ignition switch on. The ride control LED's will go dark.

Now press the "Auto" button on the ride control unit once. The red error light will continuously flash (about 0.6 Hz). This indicates that the computer is working correctly in diagnostic mode. Next press the "Auto" button one more time. Two things can happen. If the error light stops flashing, this indicates that all is correct with all shocks. If on the other hand you see a series of rapid flashes count them. They will repeat in either of 4 formats spaced apart by a period of no flashes. The flashing pattern indicates which wheel is at fault according to the following format:-

Flash Frequency	Wheel in which there is a problem shock absorber
One flash per second	Front left wheel shock absorber
Two flashes per second	Front right wheel shock absorber
Three flashes per second	Rear left wheel shock absorbers
Four flashes per second	Rear right wheel shock absorbers

If an error appears for the front wheels things are a little simpler than for error codes for the rear wheels. In the case of the rear wheels because there are two shocks per wheel it will be unclear which of the two shocks are at fault. Perhaps even both have failed.

If there are no problems with all the shocks the error light will come back on and flash rapidly and continuously at 5Hz.

Second Test Level.

This brings us to the second phase of diagnostic testing. This is used if a faulty shock is indicated in the above test. It checks if the problem is related to one or more of the actual shocks or is due to some other part of the suspension control system. Start the test by first pressing the "Auto" button. Again the error light will flash at 0.6Hz. Disconnect the electrical connection going to the shock absorber. It is a 3 pin socket (see figure 6). Obtain a simple voltmeter. Press the "Auto" button one more time. Measure the voltage between pin 2 and 3 of the connection from the car to the shock absorber. It should be between 0.7 to 1.3 volts. The voltage between pin 1 and 3should be between 10 to 15 volts. If these values are correct the system itself is OK and the failure is in the shock absorber(s) itself. Sometimes the shock is OK, its the electrical connection in the connector that is bad. A spray of TV tuner lubricant can quickly fix the problem!


Figure 6. 3 pin electrical socket to front shock. Note also nozzle for hydraulic fluid to raise car		Figure 7. Wires of electrical control to rear shock absorbers	Figure 8. Electrical connection socket for rear shock. (Two per wheel).

Third Test Level.

The third test of the suspension system is to make sure the speed sensor to the ride control system is working correctly. Again we press the "Auto" button. The error light will flash again at 0.6Hz. Press the auto button again. At this point the error light will stay on. Drive the car at increasing speed. The light should start flashing at about 20 MPH. If it stays permanently on, there may be a connection problem with the speed indicator in the car. This will lock the suspension into a (stiff) 3 setting mode.

After all tests are completed remember to reset the computer switch under the passenger side dashboard. Switch off the ignition switch, this will reset the computer controlled shock absorber to its normal functional mode.

This page was last modified on 03/12/2014

This page was last modified on 09/06/2014